Diode lasers output radiation at one frequency or frequency interval, further the diode laser may emit radiation at a further frequency or frequency interval, but that frequency, frequencies or frequency interval may not be the desired frequency interval. Therefore there is a need for providing a system that allow the emitted radiation to be transformed to the desired frequency or frequency interval. The term frequency and wavelength may be interchanged throughout the description using the physical relation between frequency and wavelength.
Related system and method are described in publications such as U.S. Pat. No. 5,644,584 wherein a laser system comprising a distributed Bragg reflector or distributed feedback tunable diode laser coupled to a quasi-phasematched waveguide of optically nonlinear material is disclosed.
In general the output from a laser system may have many uses, e.g. as light source in a measuring system, a system for generating short optical pulses etc. Present systems have several drawbacks, such as high complexity which may result in high maintenance and high cost.
Hence, an improved laser system would be advantageous, and in particular a more efficient laser system which is easily cooled would be advantageous. Further it would be advantageous to provide a laser system having low intensity noise, as this noise type is particularly disadvantageous.